Method for the separation of stearin and olein from fatty acid mixtures



Patented Aug. 20, 1935 i UNITED STATES PATENT OFFICE- METHOD FOR THE SEPARATION OF STEARIN AND OLEIN FROM FATTY ACID MIXTURE S Ernst Alfred Mauersberger, Maarssen,

.near Utrecht, Netherlands I No Drawing. Application March 1, 1933, Serial No. 659,178. In Germany March 15, 1932 f 4 Claims. (Cl. 87-4) The present invention relates to a method for such a manner that it is dispersed colloidally or the separation of stearin and olein from 'fatty 'as an emulsion in the solution. acid mixtures of all kinds containing them. Various methods of colloidally dispersing or Hitherto stearin has generally been prepared emulsifying the water in the fatty acid solution 5 by the so called double press method. This methmay be employed. For example, alcohols, or 5 0d takes considerable time and requires expenother bodies containing considerable quantities of sive apparatus. Apart from this, not all fatty water, and which dissolve wholly or partially in acids can be expressed by this method. Morewater as well as in the solvent or the fatty acids, over, it is necessary to endeavour to obtain a may be added to the solution. Upon cooling crystalline structure by mixing different fatty the solid fatty acids separate out in an easily fil- 10 acids, so as to permit of the pressing operation. trable form.

Further, olein, on account of its high melting If high percentage. alcohol is employed it dispoint and its little crystalline form can only solves without cloudiness. Since, however, very be worked up with difiiculty to liquid olein. large quantities are necessary in order to attain 5 Attempts have frequently been made to rethe desired object, then upon distilling off the place this pressing operation by employing 501- solvent, partial esterification would take place, vents out of which to crystallize the stearin whereby the end products would be useless. If, upon cooling. These however have been found on the other hand, the operation is carried out to be impracticable owing to certa n diffic with water only and without alcohols, a paste is T use Of 31001101 as a Solvent has y times obtained which filters very badly and only incom- 20 been proposed. Since, however, for reasons of i t l' e n my t v n alcohol, must be recovered, Apart from alcohols, ketones, aldehydes and the 31100110]. is distilled Ofi and 1113011 distillation I so forth emulsifiers can be employed such as ulan esterification of the alcohol with stearin or phonation products of organic id 1 h 1 olein takes Place 50 that the pmducts are ketones and so forth, their estersor salts and also 25 salts of fatty acids. Emulsifiers may also be used, Speclfication 156,259, 1t has been together with alcohols, ketones, aldehydes ,or the Proposed to Separate lower from higher moleculike, for introducing the necessary water. The 1341" Weight fatty acids by making use of Solvent first group, namely the sulphonation' products are Alcohol was proposed as a Solvent and it was employed in aqueous solution, whilst the salts of 30 posed to the powerpf the V? to fatty acids are actually formed in the fatty acids solve the high molecular acids, by addition of waby Stirring in solutions or suspensions in water ter or toprecipitate the higher molecular of oxides, hydroxides, or carbonates of metals or fafltty aclds q- Solutlon of the fatty n nitrogenous bases, the water being bound in colmixture by addition of water. Further a method loidal form in the fatty acids 35 has been proposed in which liquid sulphur dioxide If the fatty acids to be employed already com alone or in mixtures with other Solvents was tain water then account must betaken of this g g wg pi out g i f g acids fact in order to effect colloidal dispersion of the rom a y aci mix ures. is me, o neces- 40 sitates a complicated -,apparatusand demands 2 222 1 2 5: 22: 2;g igg g gxi g giggf the .special precautionary measures on account of q I th f tt t b d the troublesome and noxious odour. It is also In cases y am 9 e emp Dye may already contain an emulsifying agent, for

not practicable to use petroleum benzine as a f d h t solvent for fatty acids, from which to crystallize example a me percentage 0 map m t a case the addition of water alone permits of the i c t ids 45 out stearin upon 6001 ng Sm e the fa ty ac formation of a colloidal solution or emulsion.

harden as a paste, from which no olein can be t The wet crystalline mass obtained upon cooling filtered off.

t h now been found according to this inventhe fatty acid solution 15 treated in a filter press. The olein remains in the solvent and can be tion that stearin and olein can be practically and economically recovered from fatty acids of easily filtered Hard Cakes 0f the Sohd fatty 50 all kinds by crystallizing their solutions in oxyacids remain in'the filter D Both p duc s gen free hydrocarbons such as petroleum benare freed from the solvent in kl'lOWll manner.

zine, benzene, toluene, chlorinated hydrocarbons In h s pr s the filter cloths be d for and the like, or mixtures thereof, it before 0001- a month without being clogged or stopped. mg, water is added to the fatty acid solution in In order that the invention may be W under- 55 Intermediate product stood the following examples will be given by way of illustration only:-

Example 1 1000 kg. of melted twitchelled bone fatty acids with the following analysis numbers:

are stirred together with 700 kg. commercial extraction spirit fractionated from crude petroleum with a boiling point of 105 to 175 C., in suitable vessels with cooling jackets and slowly operating stirring mechanism. 50-70 kg. of methyl alcohol are added whilst stirring, to the clear solution at 35 C., whereupon a colloidal cloudiness 'is produced. The stirring is slowly continued with strong cooling until the temperature of the fatty acid solution is about 10-l2 C. at which temperature it becomes a wet crystalline mass or pulp. The pulp is. passed through filter presses at a moderate pressure. Very firm cakes are formed in the presses whilst the clear olein containing mother-liquor runs away.

The stearin cakes are taken out of the filter presses and melted. Thereupon the greater part of the added dilute alcohol is separated and is used with the next charge. All of the methyl alcohol still contained is distilled off from the cakes at about C. and after this the solvent is driven off by blowing steam through. After distilling off the solvent the stearin has the fol. lowing analysis numbers:

Melting point 52-54% Iodine number 5- 7 If a higher melting point and a lower iodine num I ber is to be obtained, the cakes coming from the filter presses are thoroughly stirred at 10-12 C. with about the same quantity of the aforesaid spirit as previously employed for about an hour. and passed again through the filter presses, the filtrate being used for a fresh charge. The stearin cakes treated as above described, after driving off the solvent now have the following con-- stants:

Melting point 56-58 c. Iodine number 2- 3 The mother-liquor from the first pressing is cooled further to about 3 C. for separation of the small quantities of stearin still contained in the solution, whereby a further small crystal1iza-- tion takes place, and then filtered. This stearin is specially treated since it contains oxystearic acid which, during the subsequent distillation is converted into iso-oleic acid. The filtrate is'then freed from solvent whereby firstof all, as before, methyl alcohol is obtained. There remains an olein with a solidification point of 10-11 0., which by cooling and filtering can be brought to any technically usual solidification point.

' In the above example the following yields were obtained:-

' B 440 80 Olein of emulsification point 1011f C. 470

Lesses' 10 stearin of melting point 52-54 C Example 2 Operating as in Example 1, 1000 kg. of twitchelled bone fatty acids are reacted with 30 litres of a 25% aqueous ammonia solution and the emulsification is carried out with vigorous stirring. The fatty acids so pretreated are stirred cold at 35 C. with 800 litres of heavy benzine of boiling point 125 C. The stirring is slowly continued with strong cooling until the temperature of the fatty acid solution is about 10-12 C. at which temperature it becomes a wet crystalline mass or pulp. The pulp is passed through filter presses at a moderate pressure. Very firm cakes are formed in the presses whilst the clear olein-containing mother-liquor runs away. Upon driving off the solvent from the stearin cakes the small percentage of fatty acid ammonia splits up again into fatty acid and ammonia.

Whilst in the foregoing specific examples of the application of this invention have been described it is to be understood that various modifications may be made without departing from the scope thereof.

I claim:-

1. The herein described method of recovering stearin and olein from fatty acid mixtures, which method comprises dissolving the fatty acid mixtures in an organic solvent selected from the class consisting of hydrocarbons free from oxygen, incorporating water in said solution and forming a colloidal dispersion or emulsion of the water in said solution, cooling the solution and thereby crystallizing its stearin contentand recovering the crystallized stearin.

2. The herein described method of recovering stearin and olein from fatty acid mixtures, which method comprises dissolving the fatty acid mixtures in an organic solvent selected from the class consisting of hydrocarbons free from oxygen, introducing a soap containing water into said solution and forming a colloidal dispersion or emulsion of the water in said solution, cooling the solution and thereby crystallizing its stearin content and recovering the crystallized stearin.

3. The herein described method of recovering stearin and olein from fatty acid mixtures, which method comprises dissolving the fatty acid mixtures in an organic solvent selected from the class consisting of hydrocarbons free from oxygen, introducing alcohol containing water into said solution and forming a colloidal dispersion'or emulsion of the water in said solution, cooling the solution and thereby crystallizing its stearin content and recovering the crystallized stearin.

4. The herein described method of recovering stearin and olein from fatty acid mixtures, which method comprises dissolving the fatty acid mixtures in an organic solvent selected from the class consisting of hydrocarbons free from oxygen, introducing into said solution a water emulsifying sulfonated organic product containing water and forming a colloidal dispersion or emulsion of the water in said solution, cooling the solution and thereby crystallizing its stearin con- ERNEST ALFRED 

